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interfacing microcontroller with pstn
dear all, my project is to make biomedical hand held unit that is used in house. simply, i need to read data from different biomedical sensors via usb port and send it to a microcontroller (task1: i need to choose asuitable controller), then t...
Microcontrollers :: 18 Sep 2009 1:30 :: elrayes :: Replies: 5 :: Views: 348
i need urgent help in >> telephone signaling module
hi all i got this task today and i have to solve it within two days i really need any helpthe task :design and implement a telephone signaling module that generates standard signaling tones ( dial, ringing, ringing back, busy tone).that is to say to...
Digital communication :: 22 Aug 2009 22:59 :: k_general :: Replies: 0 :: Views: 131
curious question on t-568-b network pin out & wiring
hi,i am curious to find out why our computer network cablehave the follow color scheme standard.why dont they choose to arrange the twisted pairjust next each other, instead of being split up like pin 3 & 6.any reasons you can think of?pin # t-568...
Electronic Elementary Questions :: 16 Jul 2009 14:17 :: siongboon :: Replies: 4 :: Views: 283
how to enable pulse dialling in a telephone ?
i want to enable pulse dialling in a project that uses a landline telephone and a microcontroller.1>should i use a dedicated ic ? or will a relay switch do ?2>if i use pulse dialling technique, which relay should i use? a reed relay?3>how many lines ...
Electromagnetic Design and Simulation :: 14 Mar 2009 22:09 :: mvs sarma :: Replies: 7 :: Views: 372
query regarding working of telephone
hello everybody, im currently working on my final year projectthis is the idea it is based on:a circuit (transmitter) mounted on a door is made to send a pulsed ir beam across to a circuit (receiver) mounted on the wall adjacent to the door.a microco...
Network :: 01 Mar 2009 23:22 :: FvM :: Replies: 1 :: Views: 186
help with connecting mt8870 and isd chip
im trying to build an audio dial tone. so when the person dials a number on the phone pad, they will be able to hear out loud what number or button they pushed verbally instead of a dial tone.---------------------------------------------------------...
Professional Hardware and Electronics Design :: 21 Dec 2008 6:23 :: sabeti_1990 :: Replies: 3 :: Views: 603
how to get the dial number from gsm module
i am engaged in a remote controll system, which get the instruction from the dial number. for example: a dials b, and b picks the phone, then a dials 1, how can b get the 1 ? is there an at instruction to get the number information from the gsm modul...
Network :: 05 Nov 2008 5:21 :: raychenchina :: Replies: 2 :: Views: 318
dtmf problem!!
i generate dtmf with micro controller(avr). how can i connect it to phone lines ..please give schematices. thanks...
Microcontrollers :: 04 May 2008 11:54 :: lerameur :: Replies: 25 :: Views: 1079
egypt telephone interface
i am designing a telephone interface for use in egypt.can anyone help me find the specifications for the telephone line?my customer is measuring 50 volts on-hook and 7-9 volts off-hook which is standard. but when i ask him to measure the ac voltage, ...
Analog Circuit Design :: 17 Mar 2008 19:25 :: zolam :: Replies: 9 :: Views: 831
teleremote control
here is a teleremote circuit which enables switching ‘on’ and ‘off’ of appliances through telephone lines. it can be used to switch appliances from any distance, overcoming the limited range of infrared and radio remote controls.the circuit described...
Professional Hardware and Electronics Design :: 05 Feb 2008 22:00 :: tamilmaran :: Replies: 0 :: Views: 384
dtmf
actually i wanted to know what type of tone would be available at pin 7. after constructed the circuit i gave tone o/p to input to the amp. but when i press the key it doesnt make any sense.. will it make sound if the circuit works?.. or let me know...
Electronic Elementary Questions :: 03 Feb 2008 14:02 :: laktronics :: Replies: 1 :: Views: 159
interfacing dsc alarm using contact-id
hii´m working on a interface to a dsc alarm using the contac-id protocol. i need to emulate a telephone line and generate dial-tone and handshake signals. i have a prototype working, but sometimes the alarm misses the signals.the line emulation is do...
Hobby Circuits and Small Projects Problems :: 31 Jan 2008 12:11 :: etolocka :: Replies: 2 :: Views: 555
ss7, sus and res message meaning?
i am getting sus and res messages in isup tracer.can someone explaing what these are ?? additionally if some one has any short document about this, itll be highly appreciated..regards,naveed...
Digital communication :: 23 Jan 2008 9:21 :: mazas3ad :: Replies: 10 :: Views: 954
telephone questions
what frequencies are produced in telephone line and how i can detect them?what about voltage?what is difference between tone and pulse ?do you have any books about circuit of telephone or technologies of telephone ?...
Network :: 22 Jan 2008 7:14 :: Naveed Alam :: Replies: 9 :: Views: 245
call setup in pstn?
how call setup works in pstn?who can introduced a book or a good tutorial about this subject?...
Electronic Elementary Questions :: 16 Jan 2008 20:54 :: well-read :: Replies: 3 :: Views: 136
telephone line ???
how can i detect signal on telephone line ( use for both pulse and tone dial) use mcu ?may anyone give idea to me ? and diagram, tutorial, ...?...
Professional Hardware and Electronics Design :: 04 Dec 2007 3:15 :: funnynypd :: Replies: 5 :: Views: 438
help about auto dialer
hi alli have sudied the voltages and current changes in phonelineand i want to study about how to connect a microcontroller to phoneline and dial a number with a microcontrollerand more important than it ,how to analyse the busy and waiting conditio...
Microcontrollers :: 02 Dec 2007 18:58 :: BobK :: Replies: 3 :: Views: 279
need to make pulsating buzzer - as small as possible
im working on a little project and could use a fair bit of help.i bought a pulsating piezo buzzer from radio shack (part # 273-066), hooked it to a 9-volt battery and, ta-dahhhh, i have a beeping device. thats 1.0. the pulsating piezo buzzer is larg...
Analog Circuit Design :: 29 Apr 2007 9:15 :: ldanielrosa :: Replies: 2 :: Views: 429
tone dial generator
what is a tone dial generator?can anyone share a tone dial generator circuit?thanks in advance......
Electronic Elementary Questions :: 25 Mar 2007 18:11 :: rogerynt :: Replies: 1 :: Views: 204
pstn standars
where can i get information on pstn standars, i want to know the voltage and current levels when getting dial tone, or a ring, and things like that.....
Digital communication :: 13 Feb 2007 2:23 :: alzomor :: Replies: 3 :: Views: 138
automatic telephone dialer when triggered
hi people, i want a automatic telephone dialer when triggered circuit diagram. using a microcontroller is best suited and should have a minimum of 2 trigger inputs.thanks in advance,pravardhan...
Electronic Elementary Questions :: 06 Feb 2007 15:20 :: pravardhan :: Replies: 3 :: Views: 201
[req] telephone ic which can be connected to a uc
hi all,i want to design a circuit like that is attached. there is an adc ic connected to a microcontroller. the micro-controller collects the digital data.it is needed that the collected data be transferred every day (or every week) through telephone...
Microcontrollers :: 25 Jan 2007 10:24 :: aNdreiBuuu :: Replies: 6 :: Views: 303
help me about communicating pic with cellular phone...
hi, i have to communicate pic 16f877 with my nokia 7250i mobile phone. i want to make a call by using pic. but theres a problem i couldnt solve. i sent the link of the schematic of circuit, and wrote my codes below. waiting for your help... <img ...
Microcontrollers :: 12 Nov 2006 7:24 :: budhy :: Replies: 8 :: Views: 378
auto dial
hi, some one had auto dial schematic, i need to autocall via fix phone....
Hobby Circuits and Small Projects Problems :: 10 Nov 2006 3:20 :: curhat06 :: Replies: 2 :: Views: 216
project related to telephone
i need to design an easy calling card system through which a user can input his password and call.i also need to maintain a database system through which i can keep track of the balance of the user .the whole system must be a computer based system wi...
Analog Circuit Design :: 07 Nov 2006 13:39 :: siongboon :: Replies: 3 :: Views: 336
modem and broadband
can anyone explain me how internet works that is how broadband services work and why does broadband connection requires a special router and wheras dial up connection uses a 52kbps modem why so and how modem factor changes plz help...
Electronic Elementary Questions :: 08 Aug 2006 10:46 :: mmike :: Replies: 8 :: Views: 1095
dial tone
whats the significance of dial tone in a telephone???...
Analog Circuit Design :: 30 Jun 2006 19:14 :: bauer :: Replies: 2 :: Views: 225
dtmf decoder using microcontrollers?!
does anybody have an idea how to make a microcontroller (pic, atmel..) decode dtmf signals without the use of an external decoding chip?can u help?...
Microcontrollers :: 03 Jun 2006 10:25 :: apk_1010 :: Replies: 36 :: Views: 2844
using cm8870-kt3170's opamp out
my circuit already contains cm8870 for dtmf decoding. i want to use its opamp output to my mcu input for detecting other tones (call back, dial tone etc). is the is it posible? opamp out is about 5vpeak while tone occurs?ps: i dont have scope ...
Professional Hardware and Electronics Design :: 19 May 2006 21:41 :: zolam :: Replies: 4 :: Views: 366
telephony systems unwanted dc voltages
can anybody tell me how unwanted dc voltages can be generated in twisted pair cables laid for telephony purposes underground. i think that emi and other couplings only generate ac voltages. can there be any reason?...
Electronic Elementary Questions :: 23 Apr 2006 8:30 :: throwaway18 :: Replies: 3 :: Views: 201
require a simple telephone line simulator!
phone lines,i am looking for a simple telephone line simulator.requirements. 1 . line voltages 48v on hook and 10-12v off hook. 2. ringing signal to be generated at will . 3. dial tone ,optional not must links or suggession...
Microcontrollers :: 05 Mar 2006 13:34 :: eng_ahmed22 :: Replies: 5 :: Views: 384
pbx design help.
hi every body.i want to build a pbx, with only internal telephon lines (no co interface at the begining) let us say 4 internal lines,can any body suggest schamatic or block diagram or anything to start???i have some experience (2 years) in installing...
Analog Circuit Design :: 15 Feb 2006 16:00 :: ptmsl :: Replies: 1 :: Views: 327
pbx design help.how to start???
hi every body. i want to build a pbx, with only internal telephon lines (no co interface at the begining) let us say 4 internal lines, can any body suggest schamatic or block diagram or anything to start??? i have some experience (2 years) in install...
Professional Hardware and Electronics Design :: 15 Feb 2006 15:08 :: IanP :: Replies: 1 :: Views: 270
tone generator
now i want to circuit to make tone for telephone system dial tone , busy tone , nu tone , ringback tone...
Hobby Circuits and Small Projects Problems :: 11 Jul 2005 7:51 :: IanP :: Replies: 1 :: Views: 165
house alarm systems and the fixed phone line
e of an alarm event the system can notify the company which provides the service of guarding the object. i am interested if the phone interface inside of systems like this is a real analog modem on a dialup line(pots) or the communication used in sys...
Professional Hardware and Electronics Design :: 16 May 2005 6:36 :: najam696 :: Replies: 28 :: Views: 7666
dtmf question
hi,im trying to do a project where it requires auto dialing, i.e. to dial a specific number when triggered to do so. well, my teacher suggested i recorde the number (sound of numbers) i want to dial on a record/playback chip and play it when its time...
Microcontrollers :: 03 Apr 2005 5:51 :: Jack// ani :: Replies: 19 :: Views: 1212
modem communication without telephone?
maybe some of you may react with crazy comments, but before that, may i say that i am not the proponent of this, i just want to ask your point of view.so what do you think? is it possible to connect two modem directly by wire not through the pstn, an...
PC Programming and Interfacing :: 13 Mar 2005 10:22 :: glenjoy :: Replies: 8 :: Views: 366
atd <phone #> problems
hi1.- ericsson r5202.- drs-11 data cable (serial com port) conected on pc3.- winxp hyperterminal softwarei make a call using: atd <phone number><cr> ====> its working very wellwhen call is on, then i try to send dtmf using: at+v...
Microcontrollers :: 07 Mar 2005 21:50 :: gidimiz :: Replies: 3 :: Views: 1140
how to transmit data over 2-wire dc power line ( e.g 5v)
hi,does anybody heard about cicrcuits that can transmit serial data and suply circuits over 1-pair (2-wire only ) power line. ( up to 2400...4800 bd, up to 2000ft. )ive heard about hart protocol, but its industrial one. i want make my own drivers an...
Microcontrollers :: 01 Mar 2005 12:23 :: vdaniel :: Replies: 12 :: Views: 2769
modem connection
is it possible to connect two modems directly together, linkup and tranfer data. if so, then how? the one pc runs winxp and the other win98.sputnik...
PC Programming and Interfacing :: 07 Nov 2004 0:10 :: davorin :: Replies: 1 :: Views: 312
dial tone generator
i have this device that only works if it is connected to the phone jack and hears a dial tone.on my pc i have a program that generate the dial tone but how would i go about connecting this device to my pc so that it hears the fake dial tone?...
Hobby Circuits and Small Projects Problems :: 12 Sep 2004 9:29 :: mhamed :: Replies: 13 :: Views: 1983
need a tone generator
i want to build a tone generator to inject busy tone or dial tone into pcm channel. how can i produce such 64k signal of busy tone or dial tone?any help is appreciated....
Professional Hardware and Electronics Design :: 14 Jun 2004 20:49 :: mbyka :: Replies: 1 :: Views: 261
a/d on telephone line
what would be the best way to isolate an a2d (like adc0803) connected to a telephone line in order to measure dc voltage and ac voltage (while ringging) on it. with ac it is easier as a 600r can be connected between the line and the other side of th...
Professional Hardware and Electronics Design :: 10 Mar 2004 9:48 :: Pazam :: Replies: 7 :: Views: 681
simulation of pstn switch interface
dear all,i am going to make a simulation kit for the telephone line subscriber interface from the pstn switch side and i need to generate the dial tone and -48 vdc using a simple design .. any suggestions ..?regardsmeshmesh...
Professional Hardware and Electronics Design :: 29 Dec 2003 9:18 :: meshmesh :: Replies: 0 :: Views: 216
slics
can some suggest good slic ics ?...
Professional Hardware and Electronics Design :: 17 Nov 2003 19:41 :: digidot :: Replies: 7 :: Views: 804
problem with repairing modem
i plugged my internal modem in the electricity outlet .i noticed my mistake after a while but the modem didn`t work anymore . i checked the board and substituted one of the resistors that was burned . it seems that the board dosen`t have any other pr...
RF, Microwave, Antennas and Optics :: 31 Oct 2003 7:48 :: House_Cat :: Replies: 1 :: Views: 422
metallic line testing circuit design reference
ive me some reference circuit or suggestion, i will really apprecate.the testing items(1) line resistance(2) line capacitance (ren testing)(3) current(4) dc/ac voltage(5) dtmf generation/detection(6) dial pu......
Professional Hardware and Electronics Design :: 20 Oct 2003 9:21 :: calvinhorng :: Replies: 0 :: Views: 318
how to generate a telephone dial tone in europe
hi, is there an integrated circuit capable of generating a telephone dial tone which is ussually generated by the telephone switch itself. what would be the timing sequence of the dial tone, not the continuos tone like in america. is the ...
Professional Hardware and Electronics Design :: 05 Jun 2003 12:07 :: papyaki :: Replies: 1 :: Views: 340
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how can i fix a (no dial tone) modem problem?
problems & problems..... thats how we learn...ok.. i have creative pci v90 modem... something happened to the phone line (i think high voltage chock) and after i got no dial tone message when i use it... the problem was: zener diad has beed dameged....
PC Programming and Interfacing :: 03 Mar 2003 18:52 :: Analyzer :: Replies: 9 :: Views: 2094
help with c program
i have a bit of a problem, the following code works fine, but when i try to make a function out of the contents of the functions block, it compiles, but will not run.made a file called cancelcall.cadded contents of the block marked functionsincluded ...
PC Programming and Interfacing :: 24 Dec 2002 9:58 :: GrandAlf :: Replies: 7 :: Views: 1169
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